Alternators are commonly used as a source of electrical power in automotive vehicles, boats, aircraft, and various other applications. One of the problems associated with these alternators is the contamination of the carbon brushes which slidingly contact the slip ring of the alternator. In most applications, these brushes are exposed to water, salt, and other contaminants Within the engine compartment of the vehicle.
Another problem is that helical springs are used to bias the carbon brushes in sliding contact with the alternator slip rings. The force produced by these helical springs is variable as a function of their extension. As a result, the force produced by the helical springs on a new carbon brush is greater than necessary to ensure that after wear of the brush and the extension of the helical spring, the force remains sufficient to maintain the brushes in contact with the slip rings. This excessive force increases the wear on the carbon brushes and reduces their life expectancy.
Another problem faced with existing alternator brush holders is during assembly in which the pigtail connection from the brush to an electrical terminal has to be threaded through a small hole. This is a time consuming assembly task. Additionally, the small hole through which the pigtail is inserted needs to be sealed with an epoxy to inhibit contamination by water, salt and other undesirable elements.
The brush holder device taught by Nimura in U.S. Pat. No. 4,404,487 is representative of brush holders currently in use. This brush holder device has helical springs biasing the carbon brushes in sliding contact with the slip rings of the alternator and the connector pigtails are inserted into a hole provided in the terminal plate and soldered thereto.
Koster, in German patents DE 3627529 and DE 3726894 discloses a brush holder where the pigtail is attached to a terminal at the front of the holder. Like Nimura, the brush holder disclosed by Koster has a helical spring biasing the carbon brush against the slip rings.
The invention is a regulator and brush holder assembly directed toward the elimination of these problems.